Warra Flux Data Release 2021_v1

This data release consists of flux tower measurements of the exchange of energy and mass between the surface and the atmospheric boundary-layer in semi-arid eucalypt woodland using eddy covariance techniques. It been processed using PyFluxPro (v3.3.0) as described in Isaac et al. (2017), https://doi.org/10.5194/bg-14-2903-2017. PyFluxPro takes data recorded at the flux tower and process this data to a final, gap-filled product with Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER). For more information about the processing levels, see https://github.com/OzFlux/PyFluxPro/wiki. Eucalyptus obliqua forests dominate the vegetation below 650 m where they exist as fire-maintained communities. On fertile soils these forests attain mature heights in excess of 55m: the tallest E. obliquareaches a height of 90m. The flux station is installed in a stand of tall, mixed-aged E. obliqua forest (77 and >250 years-old) with a rainforest understorey and a dense man-fern (Dicksonia antarctica) ground-layer, on a small flat of elevation 100 m adjacent to the Huon River. The understorey vegetation progresses from wet sclerophyll (dominated by Pomaderris apatala and Acacia dealbata) to rainforest (dominated by Nothofagus cunninghamii, Atherosperma moschatum, Eucryphia lucida and Phyllocladus aspleniifolius) with increasing time intervals between fire events. The site supports prodigous quantities of coarse woody debris as is characteristic of these fire-maintained eucalypt forests on fertile sites in southern Tasmania. The soil at the flux site is derived from Permian mudstone and has a gradational profile with a dark brown organic clayey silt topsoil overlying a yellow brown clay. The climate of Warra is classified as temperate with a mild summer and no dry season. Mean annual precipitation is 1700 mm with a relatively uniform seasonal distribution. Summer temperatures peak in January (min. 8.4°C – max 19.2°C) with winter temperatures reaching their lowest in July (min 2.6°C – max 8.4°C).The instruments are mounted at the top of an 80m tall guyed steel lattice tower. Supplementary measurements above the canopy include temperature, humidity, windspeed, wind direction, rainfall, incoming and reflected shortwave radiation and net radiation. An open-path gas analyser (EC150) was replaced by a closed-path gas analyser (EC155) at the end of Jan 2015.Soil moisture content is measured using Time Domain Reflectometry, while soil heat fluxes and temperature are also measured. Micro-meteorology (CO2, H2O, energy fluxes), meteorology (temp, humidity, wind speed and direction, rainfall) taken from the Warra Flux Site from 2013 to late 2016. Data incomplete due to ongoing problems since changing the open-path IRGA to a closed path system (CPEC200) during 2015. Soil data (moisture, heat flux, temp) complete for time period. For additional site information, see https://www.tern.org.au/tern-observatory/tern-ecosystem-processes/warra-tall-eucalypt-supersite/ .

本数据集发布内容为采用涡度协方差技术（eddy covariance techniques）获取的半干旱桉树林地地表与大气边界层间能量与物质交换的通量塔观测数据。本数据集已按照Isaac等人（2017）的方法，使用PyFluxPro（v3.3.0）完成处理，相关文献链接为https://doi.org/10.5194/bg-14-2903-2017。PyFluxPro可将通量塔采集的原始数据处理为最终的间隙填充数据集，将生态系统净交换（Net Ecosystem Exchange, NEE）划分为总初级生产力（Gross Primary Productivity, GPP）与生态系统呼吸（Ecosystem Respiration, ER）。如需了解更多处理等级相关信息，请参阅https://github.com/OzFlux/PyFluxPro/wiki。

海拔650米以下区域以斜叶桉（Eucalyptus obliqua）林为主，该群落为火维持型植被。在肥沃土壤上，这类林分的成熟高度可达55米以上，其中最高的斜叶桉株高可达90米。本通量站安装于一片高龄混龄的斜叶桉林分中（林龄分别为77年及250年以上），林下为雨林植被，地表覆盖密集的南极蚌壳蕨（Dicksonia antarctica），站点位于毗邻霍恩河的海拔100米小型平坦地带。随着火干扰间隔时间延长，林下植被从以疏花绒萼木（Pomaderris apatala）和银叶金合欢（Acacia dealbata）为主的湿硬叶林，逐渐过渡到以假山毛榉（Nothofagus cunninghamii）、香皮檫（Atherosperma moschatum）、亮叶杯果木（Eucryphia lucida）和南极假叶树（Phyllocladus aspleniifolius）为主的雨林群落。该站点存在大量粗木质残体，这是塔斯马尼亚南部肥沃生境中火维持型桉树林的典型特征。

通量站所在土壤源自二叠纪泥岩，剖面呈渐变特征，表层为深棕色有机黏土质粉砂，下层为黄棕色黏土。沃拉（Warra）地区气候为温带气候，夏季温和，无明显旱季。年平均降水量为1700毫米，季节分布相对均匀。

夏季气温在1月达到峰值（最低8.4℃，最高19.2℃），冬季气温在7月降至最低（最低2.6℃，最高8.4℃）。

观测仪器安装于80米高的拉线式钢制格构塔塔顶。冠层上方的补充观测项目包括气温、空气湿度、风速、风向、降雨量、入射与反射短波辐射以及净辐射。2015年1月底，开路式气体分析仪（EC150）被闭路式气体分析仪（EC155）替换。

土壤含水率采用时域反射仪（Time Domain Reflectometry）测定，同时同步观测土壤热通量与土壤温度。本数据集包含2013年至2016年末取自沃拉通量站的微气象数据（CO₂、H₂O、能量通量）与常规气象数据（气温、湿度、风速、风向、降雨量）。

由于2015年将开路式红外气体分析仪（IRGA）更换为闭路式系统（CPEC200）后持续存在技术问题，部分数据存在缺失。土壤相关数据（含水率、热通量、温度）在对应时段内完整。

如需了解更多站点信息，请参阅https://www.tern.org.au/tern-observatory/tern-ecosystem-processes/warra-tall-eucalypt-supersite/。